package top.jolyoulu.core.rdd.operator.action

import org.apache.spark.rdd.RDD
import org.apache.spark.{SparkConf, SparkContext}

/**
 * @Author: JolyouLu
 * @Date: 2024/2/7 20:51
 * @Description
 */
object Spark01_RDD_CountByKey {
  def main(args: Array[String]): Unit = {
    //准备环境 [*]:表示使用当前系统最大核
    val sparkConf: SparkConf = new SparkConf().setMaster("local[*]").setAppName("RDD")
    val sc: SparkContext = new SparkContext(sparkConf)
    val rdd = sc.makeRDD(List(
      ("a",1),("a",2),("a",3)
    ))
    //合计a的出现次数
    val map: collection.Map[String, Long] = rdd.countByKey()
    println(map)

    //关闭环境
    sc.stop()
  }

}
